


Incest is everything it's said to be

by zaynandlouis



Category: Big Brother RPF
Genre: Anal Fingering, Begging, Cock Rings, Dom/sub, F/M, Half-Sibling Incest, Incest, Incest Kink, Jealousy, M/M, Masturbation, Multi, Multiple Penetration, Orgasm Control, Orgasm Delay/Denial, Pet Names, Praise Kink, Riding, Teaching, Threesome, Threesome - F/M/M, Watching, fear of penetration, references to past sex acts
Language: English
Status: Completed
Published: 2014-10-20
Updated: 2014-10-20
Packaged: 2018-02-21 21:22:53
Rating: Not Rated
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 1,928
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/2482928
Author URL: https://archiveofourown.org/users/zaynandlouis/pseuds/zaynandlouis
Summary: <blockquote class="userstuff">
              <p>so when frankie and ariana had been joking about people on twitter thinking they were incestuous, zach had thrown in a vulgar comment about how watching frankie fuck ariana might make him get over his fear of penetration, and he had meant it as a joke.</p>
            </blockquote>





	Incest is everything it's said to be

**Author's Note:**

> "goodbye zankie, hello zariana!" why not both? 
> 
> disclaimer: i'm not accusing the grandes of being incestuous, this is purely fiction. the incest depicted in this fanfic is consensual, and non-reproductive. if you feel the need to express your moral outrage in the comments section, don't. thank you. 
> 
> title is from the song sister by prince.

zach stares, mesmerized by the way ariana’s hair brushes against the tan skin of her back when she bounces. 

his mouth hangs open in a o-shape when she throws her head back, and he can’t help but stare at her chest. his mouth starts to go dry and he closes it, licking his lips.

he can hear desperate whining mixed in with frankie’s noises, and he’s not sure if they’re coming from ariana or from him. he’s torn from his thoughts by a grunted, “don’t touch yourself” from frankie, and he realizes he’s tugging at the hem of his own shirt, so he’s pretty sure the noises are his.

he sits on his hands and gulps. 

ariana never stops bouncing, but she looks over at zach and gives him a “good boy,” or something like that, zach doesn’t really notice because he’s not looking at her anymore. 

he’s looking at _frankie_. 

frankie’s still staring at him, and zach feels himself getting warmer by the second.

frankie’s doing nothing, just letting ariana do all the work and _taking_ it. zach thinks that should make frankie submissive, but it doesn’t. frankie still manages to be dominant. maybe it’s because he’s older, or maybe it’s the way he holds ariana’s hips. zach likes it, the way ariana’s skin is red and a little swollen around frankie’s fingertips. he’s pretty sure there will be bruises, and he wants some like them, on his own hips.

he rocks on his hands. 

their eye contact is broken when ariana’s hair obscures frankie’s face, flowing over his shoulder and arm. zach blinks a few times so his eyes can refocus, and he realizes they’re kissing. 

frankie’s hand comes up to hold ariana’s hair out of his face, and zach breath catches in his throat when he’s able to see frankie and ariana’s lips pressed together.

zach feels a pang of jealousy, because that should be him kissing frankie, but he also feels blood rushing to his cheeks. they’re siblings, brother and sister, and they’re kissing. zach thinks it might be wrong, but somehow frankie being gay only intensifies things. it’s like, he’s gay, but he’s so into this. and the only reason for that zach can think of is that it’s his sister. frankie likes kissing his sister. zach likes frankie kissing his sister, and he kind of wants to kiss frankie’s sister too. but mostly he wants to kiss frankie. 

zach and frankie have kissed, tons of times, but watching frankie kiss someone else gives zach the opportunity to really see just how good of a kisser frankie is. the way he cups ariana’s face, just like he usually cups zach’s, and the way he tugs on her hair, almost like the way he usually yanks zach’s. he still leads the kiss, even with ariana on top of him, and it makes zach think about when frankie lets him climb up in his lap and rut against him. 

he’s suddenly acutely aware of how hard his dick is, and how bad he wants to be in frankie’s lap.

zach starts to feel jealous again. it’s settled though, when he remembers frankie’s wearing a cock ring right now, because he promised he’d save his cum for zach. and god, zach knows it sounds like some line from a bad porno where a barely legal girl calls some old guy daddy, but it made zach’s dick hard the second he heard it. 

ariana pulls away from frankie, bracing one of her hands on his chest and using the other to rub her own clit. zach watches her bite her lip and furrow her brows, starting to raise up farther before dropping herself back down on frankie’s cock. it’s slow and it’s beautiful.  

zach pulls his eyes away from her to look at frankie again. frankie’s mouth is blood red and it’s also beautiful, but zach doesn’t get to focus on it long before ariana is whining high in her throat, throwing her head back and bouncing frantically.

frankie fucks her through her orgasm, biting his own lip at the sight of his sister so fucked out. she pants _yeah yeah yeah_ s the whole time, trying to keep her fingers on her clit despite the twitching of her body, letting out a little whiny sigh when she finally comes down from the high that makes zach’s cock twitch. 

the child in zach wants ariana to get off, to get out of his way, so he can climb on top of frankie and have his turn. maybe it’s a little sick the child in zach is so eager to get fucked, but he did just watch siblings fuck, and at his request, so yeah, he’s probably a little sick.

to be honest, zach’s not really sure how this next part works. he’s never had a threesome before, unless you count playing video games and pretending not to notice your frat brother getting a handy from some random chick in the same room as you. 

 

* * *

 

when he’d brought it up to frankie, it was a joke. they’d been together for a couple months, and still never went further than handjobs and blowjobs. frankie didn’t seem to mind, he had this thing for messing around through clothes. he liked to rub zach through his underwear or have zach mouth at his dick through his own. it worked for zach too, he’d always liked a good over the pants handjob and he had a gag reflex from hell. 

it didn’t take long for zach to realize being the more physically masculine partner didn’t make him dominant. he was a puppy for frankie, and a very submissive puppy at that. frankie had educated him with male on male sex very thoroughly, so zach knew that being submissive didn’t mean he had to bottom. but for zach it did. he realized somewhere between giving his first blowjob and receiving his first rimjob that he had no desire to top frankie, and that’s when he had his i-don’t-want-stuff-in-my-butt panic. 

it’d become a bit of a joke between them, frankie giving a sarcastic “so are you gonna let me fuck you now?” when he bought zach a present or cooked them dinner, but zach knew he didn’t _really_ expect anything. 

so when frankie and ariana had been joking about people on twitter thinking they were incestuous, zach had thrown in a vulgar comment about how watching frankie fuck ariana might make him get over his fear of penetration, and he had meant it as a joke. 

that night ariana had watched frankie jerk zach off, and they’d made plans for a threesome the following week.

 

* * *

 

apparently, zach didn’t have to know what happened next, because before he knows it he’s in frankie’s lap. frankie’s propped up against the headboard, zach’s face shoved in frankie’s neck, and frankie’s hand down the back of his undies.

"shh, baby, doing so good." frankie praises, teasing zach’s rim with his fingertips.

zach whimpers when frankie presses one finger into him, stretching him open. it burns, but the lube is cool, soothing, and frankie is careful with him.

he lifts his head and tries to get kisses, slowly fucking himself back on frankie’s fingers. frankie kisses him back, licking into his mouth sweetly and smiling into it. zach’s just so easy for him, so pliant. frankie loves it.

ariana is beside them, but she knows this is about zach and frankie, and her part is over. she’s just happy for the show. she parts her legs a bit and plays with her clit, still oversensitive from riding frankie. 

frankie gets three fingers in zach, one more than he ever has had previously, before zach is begging for it. 

"frankie, frankie, fuck," he whines against frankie’s lips, " _please_ , i need you."

"i know, kitten, i know," frankie assures, removing his fingers and reaching for a condom, already having removed the condom and cock ring he wore with ariana. 

zach grumbles at the loss of contact, but he moves back in frankie’s lap enough for frankie to get the condom and rip it open. he watches wide-eyed as frankie slips the condom over his length, and his mouth waters.

see, zach would like to be able to say he’d never really looked at guy’s dicks before frankie, but that’s not exactly true. between high school, the gym locker room, and his fraternity, he’s seen his fair share of dicks. frankie’s big, but he’s not intimidating, and his head turns this pretty purple color when he’s really close to cumming that makes zach want to kiss it.

zach can’t remember why he was ever afraid of penetration to begin with when frankie pulls him back up in his lap and lines himself up. with a hand on his hip, frankie helps him lower himself down, supporting zach when he wraps his arms around his neck. ariana is a brilliant teacher, zach concludes.

when frankie bottoms out, zach lets out a breath he didn’t know he was holding. he experimentally rolls his hips, earning him a groan from frankie and a mewl from ariana.  

alternating between massaging zach’s sides and ass cheeks, frankie murmurs sweet things while zach adjusts to having frankie inside him.

zach feels amazing, even still as he is. he’s so tight, and frankie almost wishes he could kept the cock ring on so this could last longer. 

frankie starts to shallowly thrust his hips, and zach’s breathing quickens as he nods in encouragement. he starts to meet frankie’s thrusts with his own bounces, picking up speed as he goes.

the angle changes when frankie bends one of his knees a bit, and zach lets out a high-pitched whimper in the back of his throat that makes _frankie_ whine.

frankie hits zach’s prostate with every bouce and thrust, and he’s never seen a prettier sight. there’s a thin sheet of sweat covering zach’s skin, and his back is arched now. frankie leans up to press kisses under his jaw.

"god, frankie," zach gasps, "i’m already- god, it feels so good."

zach loves it, loves having frankie _in_ him, and he hates himself for not letting frankie fuck him sooner. he feels so full, so content. his skin is hot all over and he can barely breath, but it’s so good. 

it’s over all too quickly for all of them, zach breath growing raged when frankie's hand finds his dick. he presses his lips back to frankie's, before shooting his load all over his own stomach with a whine into frankie’s mouth. frankie’s own orgasm comes while he fucks zach through his, and he’s fairly certain it’s the hardest he ever came. 

ariana rubs her clit while she watches them cum together, little gasps leaving her lips, but she doesn’t try to cum again. she’s always been sensitive, and she knows she can always get herself off again later. 

"that was so fucking hot," she comments once both boys have came down from their highs. 

"so hot," frankie agrees, helping zach lift up off him. 

zach collapses into frankie’s arms, too exhausted and too fucked out to even say anything. 

"you did so good, munchkin," frankie praises, kissing the top of zach’s head. again, zach knows it’s probably fucked up how much he likes being praised like a child for making frankie cum. he tries not to think about it too hard. 

he slips into a semiconscious state of sleep, but he’s pretty sure he can hear ariana rummaging around for her nightgown and offering to get them a warm rag. 


End file.
